Pressure reducing device for refrigerating apparatus



Nov. 28, 1950 H GOLDBERG. 2,532,019

PRESSURE DU G DEvIc 0R REFRIGERATI APPARAT Filed April 15, 1949 2 Sheets-Sheet 1 Nov. 28, 1950 H. M. GOLDBERG 2,532,019

PRESSURE REDUCING DEVICE PoR REERIGERATING APPARATUS 2 Sheets-Sheet 2 Filed April 15, 1949 www@ R R, mw ff U50 Z l I 1x Sw ww mb l m MJ r, m l11|l| 6 Nw l mm\ @wml QQ E @I w v u, E mm. EN wm um w mm \/I /W L \/M\ QM.

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Patented Nov. 28, 1950 UNITED STATES PATE NTiforFica PRESSURE aEDUciNG DEVICE Foa REFRIGERATING APPARATUS Herman M. Goldberg, Chicago, `Ill.assignor to 1:

Standard Refrigeration Company, Inc., cago, Ill., a corporation of Illinois l Application April 15, 1949, Serial No. 87.815l

1s-claims. (ci. 13s-A3) The present invention relates in general to refrigeration apparatus and particularly to an evaporator unit embodying a built-in restrictorvalve for controlling the flowof refrigerant fluid therethrough.

Any refrigeration evaporator unit, regardless of the type employed, must have some type of restricting device which will control the amount of refrigerant fluid owing into the unit. The present accepted expansion valve or the com` monly used capillary tube have proven to have many attendant disadvantages. A principal-disadvantage is that the capillary4 tube voften becomes vclogged with foreign matter in operationV of the refrigeration system. The conventional capillary tube is extremelyv dlfiicult, if notimpossible, to clean, and therefore it must, of necessity, be replaced if it becomes clogged with foreign'matter. Moreover, the inside dimension of the capillary tubing is exceedingly small, `vand '20".v4 therefore it is impossible to hold to uniformityv l by means'jof a hollowconcentric member having threaded engagement with an outer member, and

a, second concentric. member adjustably disposed inthe rst hollow concentric member.

Numerous other objects and advantages will be vapparent throughout the progress of the following speciiication-' k l The accompanying ldrawings illustrate a selected embodimentfof ,the present invention, and

f the views therein areas follows.

of dimension within the length of tubing .during-' V`A the manufacture of the tubing. I f

It is therefore an'important object ofthe present invention to provide means for circumvfentf'v ing the diiiiculty inherent in present restrictor valves and overcoming the inherent dis'advanfl tages thereof by the provision of a new and-'improved evaporator'unit having a restrictor @valve 30.

which is completely self-enclosed and whlchpr'ofl vides means by which the amount of'refrigerant fluid iowing into the evaporator unit may be ad- Fig. 2 is afdetail vlongtudinaly section through 1 vFigpl is adetailelevational view of one form .fof .evaporator unitembodyingthe refrigerant restrictor valve which'fforms a-. part of the present invention;. v

f' Ithe're'strictor valve; l

justably controlled to any required degree.. f

l' central member has axial adjustment with re- Another important object is the provision of-anf'A evaporator unit embodying abuilt-in restrictor valve which may be adjusted readily to ipro'duce the required pressure drop in the. flow of refrlg erant uid before it enters the evaporator unit. A further object .the-provision of an evapfthe cooling coils .of

and to enable the parts' therein to be cleaned; A still further object' is the provision o'f an evaporator unit having-'a refrigerant restrlctor 40` orator unit embodyingla restrictor valve whicl'i-A may be disassembledleas'ilyfto permit removal .of y' foreignvmatter which has aocumulated'therein valve comprising a cylinder having a rodscrewthreaded therein, the screw threads in the' tubular -bodymember` and the screwthreads on.'l

uniformrestricted 'passage is provided therebe'I-"V tween to permitl theflowo'f. therefrigeranttheref-' throughfas it progresses'through the valve.

Still another object of the invention resides'in the provisionof a refrigerant valve having a unilig. 3 isan enlargeddetail fragmentary secation showingv certain parts of the restrictor valve; Fig. liis a transverse section taken on the line 4-4'ofFig'.3; Y*

Fig. 5 is a detail longitudinal sectional view of a modiecl form of azrestrictor valve whereby a spect to a surrounding' member'and the surrounding member lhas-axial adjustment with respect to an outer member;.and

Fig. 6 is an'elevatio'nal view showing a modifled` form in which the centralaxially arranged member may-be adjustedulongitudinally with respect toits cooperating` member by means of d-exteriorly of the re- 'stricter valve. l 'f The particular' mbdnet of the invention Aherein illustrated.for-thepurpose of describing the invention comprises 1 anevaporator unit i of any suitable. size orshape having a restrictor valve 2 mounted .thereimff Aninlet tube 3 which may lead-,fromfthe high* fessure side of any nalfcompressor unit (not shovvnrjoins withjtnefinietendrof the valve z, as indicated atv 4, Fig. 1. jfTh'e' valve 2 may join at 'its outlet end, as indicated-,at 5, `with a refrlger-ration coilvS lwhich lis vmounted by any suitable r'means to yeither the ulterior or the exterior of the evaporator unit I. valve affords means for controlling the rate oi' ow and the pressure drop of refrigerant before it enters the coiled tubing 9 within the evaporator unit I.

The restrictor 2 comprises an elongated tubular body or cylinder 'l having an axially extending main bore 8l which is provided with internal screw threads 9 throughout its entire length. The threads 9 are of the sharp V type, having sharp V-shaped roots I and sharp v-shaped crests II, Figs. 2 and 3. The cylinder 1 may have external screw threads I2 at its inlet end to receive suitable screw threads I3 which are internally formed within a cap member I4. The cylinder 1 has a closure Wall I5 at its outlet end (at the left, Fig. 2). The closure wall Il has an integral connection with an outwardly projecting stub or neck I6 having an axial bore I1 which communicates at its inner end with the main bore 8 in the cylinder 1. The stub or neck I6 may have a plurality of externally formed screw threads I8 which are adapted to engage or grip suitable internal threads formed in the coiled tubing 6.

The V threads 9 in the valve cylinder 'I are adapted to engage screw threads I9 formed externally on an elongated internal plug or rod 20, which may be positioned within the main bore 8. The threads I9 on the plug 20 are provided with V-shaped roots 2I and flat crests 22. The shape of the threads I9 may be formed by any suitable means, such as by cutting V threads on the plug 20 and then grinding down the sharp crests to produce the fiat crests 22, Figs. 2 and 3. The intertting of the flat crests 22 of the threads I9, with the sharp V threads 9 forms a slender spiral passage 23 which is relatively triangular in cross section. This passage 23 affords a uniformly restricted course of passage for the ilow of refrigerant fluid, as the refrigerant progressively ows from the inlet end of the valve 2 to the outlet end of the valve.

Means for permitting or etlecting adjustment of the length of the passage 23 comprises a counter-bore 24 which is formed in the inlet end of the cylinder 1, the counter-bore 24 being coaxial with the main bore 8. A shoulder or step 25 is formed in the valve body I at the inner end of the counter-bore 24 to provide means for adjusting the length of the spiral passage 23, in that the degree of penetration of the plug 20 within the main bore 8 and beyond the shoulder or step 25 directly determines the amount of restriction offered to the flow of the refrigerant. The length of the restricting passage 23 increases, therefore, when the plug 20 is screwed -into the main bore 3, and decreases when the plug is screwed outwardly ci' the main bore 3.

A seal or washer 26 may be positioned between the cap member I4 andthe inlet end of the cylinder 'I, to provide a leak-prooi' hermetical seal between the cylinder and the cap member.

The cap member I4 may have an annular` grooved formed therein to receive the washer 26.

The cap member .I4 carries an axially alined stud or neck 21 which projects outwardly therefrom. The neck or stud 2'I may have external screw threads 28 which are adapted to engage corresponding screw threads 29 formed on the inner surface of a closure cap III. A passage 3I extending axially through the cap I4, and

The present restrictor through the neck or stud 2'I,` permits the user 'After the user or service man has-inserted an appropriate tool, such as a screw driver, into the kerf or slot 32, he may adjust the length of the restricted passage 23 and. consequently, the flow and pressure drop of the refrigerant fluid passing therethrough, by merely rotating the tool in the proper direction until the desired pressure drop is obtained when the refrigeration system is in operation.

A seal or washer 33 may surround the neck or stud 21 to form a leak-proof hermetical seal between the cap member I4 and the cap 30 when the cap 33 is threaded on the stud 21.

A passage 34 through which refrigerant may enter the device is formed in the cap member I4. This passage 34 extends laterally from the passage 3l and communicates therewith. The passage 34 may have a suitable screening material 35, such as wire gauze, inserted therein for the purpose of separating foreign or extraneous matter from the refrigerant before it passes through the valve 2, so that the device may not become clogged. The screening material 35 may be removed periodically from the passage 34, so that this material may be cleaned or replaced with new screening material.

The end of the inlet tubing 3 has communication with the passage 34, and may be joined to the cap member I4 by any suitable means such as by soldering or the like.

The rod or plug 20 may be solid, but it is desirable and preferable that it be provided with a longitudinally extending bore 31 which communicates with the space or expansion chamber 36, Fig. 2, at the left end thereof. The bore is closed at its inlet end as shown in Figs. 2 and 3. The bore .31 permits the refrigerant fluid to expand to a greater extent so that the temperature drop of the expanding refrigerant will be considerable. It is not altogether necessary,`how ever, that the rod or plug 20 be provided with the bore 31. as it may be solid, whereby the chamber 36 alone may be used for the expansion of the refrigerant.

The pressure reducing or restricting valve 2 serves as an extremely effective means for conf termixed with the refrigerant is screened or separated therefrom. The liquid refrigerant then flows through the passage 3I and thence into the counter-bore 24 in the cylinder 'I. Upon arriving at the shoulder 25 at the inner endo! the counter-bore 24 the refrigerant enters and progresses through the spiral passage 23 formed .between the screw threads 9 and I9 in the cylinder 1 and on the plug or rod 20, respectively. The pressure of the refrigerant is reduced successively as the refrigerant flows through the passage 23, the amount of pressure drop being determined by the depth of penetration of the plug or rod 20 in the threaded bore 8 of the cylinder l. As the liquid refrigerant reaches the end of the spiral passage 23, it expands immediately into the space 31E which is formed in the bore 3 between the left hand end of the rod 20 and the closure wall I5. 'This space 36 forms an expansion chamber for the refrigerant. The expanded.

refrigerant, which has changed into4 the gaseous state, then flows through -the bore l1 and into the coiled tubing 6 where it further expands and absorbs heat from/the surroundings. By the time the refrigerant reaches the coil tubing 6, it is in a neck 55 which receives a threaded cap 56. The

a gaseous state and is drawn into the compressor where its pressure is increased, thereby,`

back into the liquid state.

ber 54 threadedly engaging the outside of the outer casing 38. The member 54 terminates in threaded cap 56 is adapted to be removed, and

thecentral plug 46 maybe adjusted by inserting a screw driver through the opening in the neck 55. and engaging the screw driver slot 51 formed l inthe right hand en d of the plug 46. causing the refrigerant to condense and change 'I'.he` invention comprises a refrigeration evapo- .1

rator unit having a built-in restricting valve which can be used with any type of refrigerant, since any desired pressure drop may be made by proper adjustment of the position of the plug or rod .in the main bore 6. The-device may be easily disassembled for cleaning by first removing the cap member I4 from the cylindrical body l and then removing the threaded rod 20 from the bore 8 of the cylindrical body l.

Many additional advantages arise by utilizing a device of the type embodied in the invention. Vibration noises which are familiar to capillary tube installations are eliminated, whether the device is used with a household standard temperature unit or with a plate type low temperature refrigeration unit. This novel type of evaporator unit having a built-in pressure reducing valve balances the load on the compressor motor on the oil-cycle. Motors having low starting torques may be used because of this balancing feature,

The surrounding tubular member 43 may'be vadjusted by the insertion of a proper tool through the neck 55 and engaging 'the multi-sided sur- 'l facesv of the interior of the member 43, or if desired the member43'may be provided with socket members 58 to receive a spanner wrench to effect the adjustment. In'this latter instance the entire outerca'p 54v may be removed. However, the

. opening in the neck of the member 54er the screw member 54 itself maybe of such size and proportions as to permit-a proper tool to be inserted amv therefore, and the cost of manufacturing the refrigeration system isl correspondingly lower. -Also the use of the present unit eliminatestlie -use of' 36 in any convenient manner such as by set screws 46. The threaded member 39 has -inner threads 4i which threadedly receive threads 42on an interior threaded member 43. The threads 42 of the member d3 are fiattened so that a continuous spiral passage is formed between the threads therein for effecting longitudinal or axial adjustment of the member 43 with respect to the member 39, the arrangement being such-,that the plug 46 may be adjusted with respect to the surrounding member 43 and the surrounding member 43 may be adjusted with respectto the outer member 39.` The arrangement in Fig. 5, therefore, while beingsimilar tothe construction Ashown in Figs. l-li, inclusive, provides for an additional adjustment.

The modification shown in Fig. 6 is for the purpose of adjusting the central screw plug 46 exteriorly ofthe restrictor valve. This latter construction discloses a screw` member 59 which is -arrangedin the end flange or pad 46 of the housing` 39. The inletll may extend at right angles as shown in-Fig. `6and an extension rod 60 may be formed integral with the central plug 46 and f extendthrough the end 6l, there being a proper packing gland 62 and a lock nut 63 for preventing the-escape of fluid from the line 50.

The construction shown in Figs. 5 and 6, therefore, is adaptedA for double adjustment, The

' 'construction lin Fig. 5 discloses an end cap for 4i and 42. The member 43 is also provided with threads 44 on its inner surface to cooperate with threads 45 on a central threaded plug 46. The threaded plug 46 is provided with exterior threads 41 which are flattened so that when the central plug 46 is threaded in the hollow member 43 a spiral passage will be formed about the central plug 46. The central plug 46 therefore has axial adjustment with respect to the surrounding member 43, and the surrounding member 43 has threaded adjustment with respect to the outer surrounding member 39. Therefore the members 46 and 43 each have separate and independent adjustment.

The outer casing 38 may be provided with a flange-like end or pad 48 to receive a fitting 49. The fitting 49 may comprise a cylindrical opening 50 leading to the interior of the restrictor valve, Figs. 5 and 6. Fluid entering the opening 50 will then pass about the spiral passage surrounding the plug 46 and enter the expansion chamber 5| at the opposite end. The uid will then pass in the space 5| where it is free to pass through the spiral passage between the outside of gaining access to the interior of the casing, while the construction in Fig. 6 discloses an arrangement whereby the central plug may be adjsted exteriorly of the casing.

s fA' iirst'or main adjustment may be made of thesurrou'nding member 46 with respect to its cooperating member 39, and then when this adj-ustment is made it may be more or less permanent as the additional or finer adjustment may be made by adjusting the central plug 46.

The inner member 43, Fig. 5, may be reduced as indicated at 64, Fig. 5, so as to provide a chamber between the inside of the member 39 and the outside of the member 46 as clearly shown at the left hand end of Fig. 5. In this latter event the screw threads 44 may be omitted for a, predetermined length commensurate with the length of the chamber 64.

The device embodied in the invention may be manufactured at low cost and is extremely ef- `cient in operation. Therestricted spiral passage or passages 23 which produce the pressurev drop are uniform in cross section throughout, thereby overcoming the lack of uniformity found in ordinary capillary tubing. YA production run of evaporator units \may, be'made, therefore, with an assured pressure drop setting.

Changes may be made-in theform, construction and arrangement of parts without departing from the spirit of the invention or4 sacrificing any of its advantages, and the right is hereby reserved to make all such changes as fall fairly in the scope of the following claims.

Having thus described my invention, what I Y claim as new and desire to secure by Letters Patent of the United States is:

1. A restrictor valve for refrigerating apparatus for controlling the flow of fluid in a refrigeration system comprisinga centrally disposed tube having interior screw threads, a central plug having exterior screw threads engageable with the interior screw threads of the tubular member, the screw .threads of one of said members being uniformly flattened to provide a spiral passage of uniform cross-section about the central plug, exterior screw threads on the tube'and engaging screw threads on an outer surrounding member, the screw threads on one of said latter members being uniformly flattened to provide a spiral passage of uniform cross-section about the outside of the tube member.

2. A restrictor valve for refrigerating apparatus for controlling the flow of fluid in a refrigeration system comprising a centrally disposed tube having interior screw threads, a central plug having exterior screw threads engageable with the interior screw threads of the tubular member, the screw threads of one of said members being uniformly `flattened to provide a spiral passage of uniform cross-section about the central plug, exterior screw threads on the tube and engaging screw threads on an outer surrounding member, the screw threads on one of said latter members being uniformly flattened to provide a spiral passage of uniform cross-section about the outside of the tube member, and means for adjusting the tubular member with respect to the outer surrounding member.

3. A restrictor valve for refrigerating apparatus for controlling the flow of fluid in a refrigeration system comprising a centrally disposed tube having interior screw threads, a central plug having exterior screw threads engageable with the interior screw threads of the tubular member, the screw threads of one of said members being uniformly flattened to provide a spiral passage of uniform cross-section about the central plug, exterior screw threads on the tube and engaging screw threads on an outer surrounding member, the screw threads on one of said latter members being uniformly flattened to provide a spiral passage of uniform cross-section about the outside of the tube member, and means for adjusting the central plug axially with respect to the surrounding tube.

4. A restrictor valve for refrigerating apparatus for controlling the flow of fluid in a refrigeration system comprising a centrally disposed tube having interior screw threads, a central plug having exterior screw threads engageable with the interior screw threads of the tubular member, the screw threads of one of said members being uniformly attened to provide a spiral passage of uniform cross-section about the central plug, ex`- terior screw threads on the tube and engaging screw threads on an outer surrounding member, the screw threads on one of said latter members being uniformly flattened to provide a .spiral passage of uniform cross-section about the outside of the tube member, means for adjusting the tubular member with respect to the outer surrounding member, and means for adjusting the central plug axially with respect to the surrounding tube.

5. A restrictor valve for refrigerating apparatus for controlling the flow of uid in a refrigeration ,system comprising a centrally disposed tube having interior screw threads, a central plug having exterior screw threads engageable with the interior screw threads of the tubular member, the screw threads of one of said members being uniformly flattened to provide a spiral passage of uniform cross-section about the central plug, exterior screw threads on the tube and engaging screw threads on an outer surrounding member, the screw threads on one of said latter members being uniformly flattened to provide a spiral passage of uniform cross-section about the outside of the tube member, means for adjusting the tubular member with respect to the outer surrounding member, and means for adjusting the central' plug axially with respect to the surrounding tube, the adjusting means for the central threaded plug member extending outwardly of the body of the valve.

HERMAN M. GOLDBERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,162,982 Crochter Dec. 7, 1915 2,063,745 Kucher Dec. 8, 1936 2,312,834 Hahn Mar. 2, 1943 

